Question

if cos theta= -1/2, then the value of 4 tan square theta - 3 cosec square theta​

Answer 1

Answer:

8

Step-by-step explanation:

cos Ф= -1/2

Then Ф we assume in II quadrant

then cos(90+30)=--sin30=-1/2

so  Ф=120

sinФ=sin120=cos30=√3/2

cosecФ=2/√3

tanФ= tan120=tan(90+30)= -cot30= -√3

Now 4tan²Ф-3cosec²Ф

=-4(-√3)²-3*(2/√3)²

=-4*3-3*4/3

=12-4

=8